1. Field of the Invention
The present invention relates to an electronic device testing apparatus for testing a semiconductor integrated circuit element and other variety of electronic devices (hereinafter, also representatively referred to as an IC), particularly relates to a contact arm for holding electronic devices to be tested and bringing them to contact a contact portion.
2. Description of the Related Art
In an electronic device testing apparatus called a handler, a large number of ICs to be tested are conveyed to inside the handler, where the ICs are brought to electrically contact a test head and a test is conducted by an electronic device testing apparatus body (hereinafter, also referred to as a tester). Then, when the test is ended, the ICs are taken out from the test head and reloaded to trays in accordance with the test results, so that sorting to categories, such as good ones and defective ones, is performed.
As a contact arm applied to an electronic device testing apparatus of the related art, there are known two types shown in FIG. 5A and FIG. 5B.
A contact arm 105d shown in FIG. 5A comprises a holding head D1 attached to a Z-axis drive mechanism 105c and the holding head D1 is buried a heater D4 for maintaining high temperature thermal stress applied to ICs to be tested. A pressure of pressing of the ICs to be tested against a contact portion 201 is managed by controlling a motor (not illustrated) provided to the Z-axis drive mechanism 105c. 
On the other hand, a contact arm 105d shown in FIG. 5B is provided with a spring D6 between the Z-axis drive mechanism 105c and the holding head D1, and a relative inclination of the holding head D1 and the contact portion 201 can be absorbed by the spring D6.
However, the above two types of contact arms 105d had disadvantages as below.
Namely, since the contact arm 105d does not have a floating mechanism by the spring D6 shown in FIG. 5B, a relative inclination of the holding head D1 and a contact portion 201 has to be adjusted by lying a shim etc. between the Z-axis drive mechanism 105c and the holding head D1. In a mechanical adjusting method by a shim, etc., however, it is difficult to sufficiently follow the relative inclination of the holding head D1 and the contact portion 201.
Although this type of contact arm 105d does have an ability of managing the pressure for pressing by motor controlling, ICs to be tested requiring pressure management are inevitably severe on an error of inclination and an accurate test cannot be conducted if the inclination adjustment is not suitably performed. Furthermore, since the pressure management is controlled by one motor, the case where a plurality of ICs to be tested are pressed by one holding head cannot be handled.
Also, even it is possible for the contact arm 105d shown in FIG. 5B to correct relative inclination of the holding head D1 and the contact portion 201 by the floating mechanism of the spring D6, the holding head D1 does not have any space for burying the heater D4 due to the spring D6 lying there, and if the heater D4 is provided on the Z-axis drive mechanism 105c side, the spring D6 ends up blocking the heat. Accordingly, this type of contact arm was able to be applied only to handlers of a chamber type which had problems in maintenance and costs. Also, inclination can be corrected by the spring D6, but the pressure management cannot be attained because the final pressing force is a force by the spring D6.
An object of the present invention is to provide a contact arm capable of separately performing stroke management and pressure management, easily adjusting inclination and furthermore flexibly dealing with changes of a socket arrangement and an amount measured at a time and an electronic device testing apparatus.
According to a first aspect of the present invention, there is provided a contact arm for an electronic device testing apparatus for bringing electronic devices to be tested to contact a contact portion, comprising a holding head for holding said electronic devices; a floating mechanism provided between a drive mechanism for moving close to or away from said contact portion and said holding head, for supporting said holding head movable about said drive mechanism; a hydrostatic pressure cylinder provided between said drive mechanism and said holding head, for adjusting a relative pressing pressure from said drive mechanism to said holding head.
In the above invention, it is not specifically limited, but preferably, a plurality of the hydrostatic pressure cylinders are provided to one holding head.
Also, it is not specifically limited in the above invention, but preferably, the floating mechanism includes a rod for supporting said holding head and a through hole formed on said drive mechanism side for said rod to penetrate; and said one rod is provided with said one hydrostatic pressure cylinder.
Furthermore, it is not specifically limited in the above invention, but at least a holding portion of an electronic device to be tested of said holding head is made removable.
According to a second aspect of the present invention, there is provided a change kit constituting the holding portion of the electronic device to be tested made to be a shape to hold the electronic device to be tested in accordance with an arrangement and/or a amount of said contact portion.
Also, there is provided a change kit constituting the rod and holding head made to be a shape in accordance with an arrangement and/or amount of said contact portion.
According to a third aspect of the present invention, there is provided an electronic device testing apparatus comprising the contact arm or the change kit.
In the present invention, the floating mechanism enables the holding head to move about the drive mechanism, and furthermore, a relative pressing pressure from the drive mechanism to the holding head can be adjusted by the hydrostatic pressure cylinder. Therefore, pressure management can be attained by adjusting the pressing pressure of the holding head by the hydrostatic pressure cylinder.
Furthermore, by providing a plurality of hydrostatic pressure cylinders to one holding head and adjusting a pressing pressure of the respective hydrostatic pressure cylinders, it is possible to correct relative inclination of the contact portion and the holding head.
Also, by setting the pressing pressure by the hydrostatic pressure cylinder a certain value, stroke management by the drive mechanism can be attained.
Furthermore, when configuring at least the IC holding portion of the holding head removable, it is possible to deal with specifications of an arrangement and amount of the contact portion as such by exchanging only the IC holding portion formed in accordance with an arrangement and amount of the contact portion.
Also, when a rod is configured removable from the drive mechanism, it is possible to deal with specifications of an arrangement and amount of the contact portion by exchanging the rod and holding head.